Editing Detection (section)

{{Unreferenced|date=March 2018}}
In general, '''detection''' is the action of accessing information without specific cooperation from  with the sender.

In the history of [[radio]] communications, the term "[[detector (radio)|detector]]" was first used for a device that detected the simple presence or absence of a radio [[signal (electronics)|signal]], since all communications were in [[Morse code]].  The term is still in use today to describe a component that extracts a particular signal from all of the [[electromagnetic radiation|electromagnetic waves]] present.  Detection is usually based on the [[frequency]] of the [[carrier signal]], as in the familiar frequencies of [[radio broadcasting]], but it may also involve filtering a faint signal from [[noise]], as in [[radio astronomy]], or reconstructing a hidden signal, as in [[steganography]].

In [[optoelectronics]], "detection" means converting a received optical input to an electrical output. For example, the light signal received through an [[optical fiber]] is converted to an electrical signal in a detector such as a [[photodiode]].

In [[steganography]], attempts to detect hidden signals in suspected carrier material is referred to as [[steganalysis]].  Steganalysis has an interesting difference from most other types of detection, in that it can often only determine the [[probability]] that a hidden message exists; this is in contrast to the detection of signals which are simply [[encryption|encrypted]], as the [[ciphertext]] can often be identified with certainty, even if it cannot be decoded. 

In the [[military]], detection refers to the special discipline of [[reconnaissance]] with the aim to recognize the presence of an object in a location or ambiance.

Finally, the art of detection, also known as ''following clues'', is the work of a [[detective]] in attempting to reconstruct a sequence of events by identifying the relevant information in a situation.